The invention relates to reclosable fasteners for attachment to plastic film, plastic film having a reclosable fastener transversly attached thereon, bags made from plastic film having a reclosable fastener attached thereto, and methods and apparatus for making film and bags having reclosable fasteners attached thereto. Even more particularly, the present invention is related to plastic film having a reclosable fastener thereon which may be used (a) in a form, fill, and seal packaging machine to package items in a reclosable bag and (b) to make reclosable bags which may be connected to one another.
Plastic bags are well known in the art. Such bags may be used for containing a variety of items. A popular use for plastic bags is to contain and display food items such as poultry and the like. Exemplary of the prior art are the following patents:
U.S. Pat. No. 5,116,140 discloses an easy-to-open synthetic resin bag including (a) a bag body substantially composed of a pair of laminated walls made of synthetic resin films, the peripheries of the laminated walls being heat-sealed to form a sealed border region while defining an unsealed storing space within the sealed border region, (b) a tear string which is heat sealed along an imaginary opening line on the inside of one of the laminated walls, the tear string having both ends thereof heat sealed in a sandwiched condition on the corresponding portion of the sealed border region, (c) a pulling tab formed by cutting a part of one side portion of the sealed border region which corresponds to one end of the tear string, the pulling tab being tearable from the bag body integrally with the tear string, and (d) a tear string retaining portion including a transverse opening which is formed by cutting off a part of the other side portion of the sealed border region and a pair of inside and outside heat sealed portions which are located at both sides of the transverse opening, the transverse opening extending in a Direction perpendicular to the tear string such that the tear string passes through a central portion of the transverse opening. Due to such a tear string retaining portion, the separation and complete removal of the tear string from the bag is reliably prevented while assuring the easy bag opening operation.
U.S. Pat. No. 5,050,736 discloses a reclosable package including interlocking closure strips positioned outside of a hermetic seal or seal area and the method for producing same. The hermetic seal is of the easy-open or peelaway type so as to not destroy the integrity of the package or closure strips upon opening of the package.
U.S. Pat. No. 5,036,543 discloses a form, fill, seal and separate packaging machine for reclosable containers to web by a plurality of stations disposed along a path of travel of a thermoplastic web including a device to attach a pair of mated, resealable closure strips to the base web. The machine is intermittent in its operation, with movement of the web through the machine controlled so that the various steps of applying the closure strips, forming, filling, sealing and separating the reclosable containers are performed during periodic stops of the machine. The machine is further characterized by its use of two pairs of web belts to move the web through the machine. A first pair of web belts initially receive the folded web stock and partially form and completely fill the containers. The second pair of web belts overlap with the downstream end of the first pair of belts, but are disposed lower than the first belts. When the filled partially formed containers pass from the first pair of belts to the second pair of belts, the unsealed free ends are exposed for final sealing and severing.
U.S. Pat. No. 5,022,530 discloses a modified zipper elements for easy open containers having interlocking zipper elements and a tear strip for opening the container along the upper edge, wherein the bases of the zipper elements are extended upward towards the tear strip to limit the area of tearing and protect the zipper elements, and a method for making.
U.S. Pat. No. 4,909,017 discloses a reclosable bag material, method and apparatus which is a new method of making a form fill bag having a reclosable fastener thereon and a mechanism therefor wherein a continuous length of film is advanced and joined first and second fastener profile strips are laid laterally onto the film of a length substantially equal to one-half of the film width, the film is advanced and formed into a tube with the side edges folded together and seamed, the first profile strip is attached to the surface of the film prior to forming it into the tube and the second opposed interlocked profile strip is attached to the inner surface of the film after it is formed into a tube, and a cross-seam is formed in the tube above the closure strip to form the bottom of the succeeding bag, and a completed bag is cut from the film by cutting below the bottom seam and above the fastener strips.
U.S. Pat. No. 4,894,975 discloses a method and apparatus for making reclosable bags with fastener strips in a form fill and seal machine from a supply of thin thermoplastic film with the film being formed into tubular shape about a filling tube with the edges of the film brought together and joined solely by a zipper strip having reclosable pressure interlocking members thereon with the zipper strip preferably heat sealed to the film and the zipper strip having a web between the pressure interlocking members which provides a tamper-evident juncture between the edges of the film so that the web must be severed for access to the interior of a bag formed from the film, and individual bags formed from the continuous tube by filing the tube through the filling tube and cross-seaming and cutting individual bags from the continuous film tube.
U.S. Pat. No. 4,782,951 discloses a reclosable package and method of making reclosable package including interlocking closure strips positioned outside of a hermetic seal or seal area and the method for producing same. The hermetic seal is of the easy-open or peelaway type so as to not destroy the integrity of the package or closure strips upon opening of the package.
U.S. Pat. No. 4,617,683 disclosed a reclosable bag, material, and method of and a device for making same wherein in one aspect extruded resiliently flexible plastic profiled reclosable fastener strip device for reclosable bags is located across the longitudinal formation axis of the bag wall web material, and in another aspect of the invention single strip fastener strip has at one or more suitable locations there along separations across the profiles, such as notches, to facilitate bending or folding of the strip upon itself so that the self-interlocking profiles of the portions of the strip folded upon themselves are adapted for reclosable interlocking with one another. The interlockable portions of the strip may have separable air tight sealing ribs therealong. The web and fastener material and fastener assembly is especially suitable for machines wherein the bags are formed, filled and sealed.
U.S. Pat. No. 4,241,865 discloses a reclosable shipping sack and method, the sack having a pouring mouth from which discrete pourable contents may be discharged, including a primary non-reclosable stitched closure fastener across and closing the mouth against unintentional discharge o the contents and including a device such as chain stitch and rip strip for facilitating digital opening of the primary closure fastener. A secondary, reclosable fastener, desirably of the zipper type, extends across the sack mouth outwardly from the primary closure fastener and is adapted for selectively opening and closing the sack mouth after opening of the primary closure fastener. A method of making the reclosable sack is also disclosed.
U.S. Pat. No. 3,473,589 discloses a plastic bag having a closure structure and a method for facilitating same, the structure having a first thin inner layer of flexible plastic material with a first fastener element extending therealong formed of a resilient material and being of one piece with the layer, a second thin layer of flexibly plastic material facing the first layer and having a uniform second fastener element extending therealong formed of a resilient material and being of one piece with the second layer and shaped to be releasably interlocked with the first fastener element, a first outer layer positioned over the outer surface of the first inner layer and laminated thereto, the first inner and outer layers providing a first substantially monolithic wall so that the first inner layer provides a support with the layers coacting and allowing a stronger lock with a thin film, and a second outer layer positioned over the outer surface of the second inner layer and laminated thereto, the second inner and outer layers providing a second substantially monolithic wall so that the second inner layer provides a backing for the support allowing a stronger lock with a thin film, the outer layers laminated to the inner layer opposite fastener elements so as to reinforce the inner layers in the area of the fastener elements.
In accordance with the first embodiment of the present invention there is provided a reclosable bag made from plastic film having reclosable fastener assemblies thereon, film having a reclosable fastener assembly attached thereon, and a method for making reclosable bags from plastic film having reclosable fastener assemblies thereon. The reclosable bag has a reclosable fastener assembly connected to a single wall of the bag, and the film has a reclosable fastener connected to one side thereof which does not require attachment to any other portion of the film when making a bag. The fastener may have an easy bag opening tamper-proof member attached thereto to indicate if the bag has been previously opened.
The film of the invention has the advantage of having a reclosable fastener assembly completely connected thereto prior to being fed to a bag making machine or a form, fill, and seal machine, thereby eliminating the need to apply a reclosable fastener assembly during the bag making process or during the form, fill, and seal process, thereby eliminating the need for the equipment necessary to add a reclosable fastener during the form, fill, and seal process.
In accordance with the film of this invention, a film for making reclosable bags is disclosed comprising a rectangular sheet of film having two side edges and a top and a bottom edge, with a reclosable fastener assembly connected to one side of the film, and with the reclosable fastener assembly being less than half the width of the rectangular sheet of film. The film of the invention includes a fastener assembly having a first elongated fastener strip and a second elongated fastener strip wherein the first and second fastener strips can connected to the same side of the film.
The film of the invention has the additional advantage of being capable of forming a reclosable bag on a vertical or horizontal form, fill, and seal machine.
The bag and film of the invention has the advantage of allowing the reclosable fastener assembly to be located at any desired distance from the top or bottom of the bag because the fastener assembly is attached to only one wall of the bag of the invention. The length of the fastener assembly may be much less than the width of a bag formed with the fastener assembly thereon. Such small length fasteners allow liquids, powders, and other small granular materials to be poured from the bag through the fastener assembly.
A good use for the bags of the invention when the ends of the fastener assembly are not sealed to front wall of the bag is to store non-perishable items such as ice glazed food products that are not susceptible to freezer burn since air and moisture is able to enter the bag around the ends of the fastener assembly after the front wall of the bag has been penetrated to gain access to the fastener assembly or even before the bag wall has been penetrated such as when a line of perforations is utilized for allowing easy access to the fastener assembly.
In accordance with the first, second and third embodiment of the present invention there is provided a method for making reclosable bags on a bag making machine where the reclosable fastener strips are independently attached to the same side of the bag film preferably transversely to the longitudinal forming axis in-line with the bag making machine, a unique two-piece interlocking fastener assembly that minimizes the size of the opening at the fastener strip ends, film having a plurality of the unique reclosable fasteners each with two interlocking profile strips attached thereon, and an apparatus for attaching the unique fastener assembly to a sheet of film including a mechanism for supplying a continuous film of flexible bag material and a mechanism for feeding preferably the coiled reclosable profile strip material preferably transversely across the bag material film, and a mechanism for positioning, cutting, and attaching enough of the reclosable profile strip material to form a preferably transversely positioned reclosable fastener for a single bag during each cycle of the apparatus, the reclosable fasteners each being spaced a single bag length apart and each profile strip of each reclosable fastener being maintained in the interlocked position and being independently connected to the same side of the film that forms one panel of the resulting bag. The bag material can be wound into a roll in the folded or unfolded state or fed directly into a conventional form, fill, and seal machine that is in-line with the apparatus for positioning and attaching the reclosable fastener strip material to the bag material web.
In accordance with a fourth embodiment of the present invention there is provided a chain of coilable interconnected reclosable bags and a method for making the same. A chain of bags are interconnected by a series of preferably transverse cross-seals including a plurality of spaced tearlines between adjacent bags. Each bag of the coilable chain includes preferably a transversely positioned reclosable fastener secured to the outer or inner surface of material that forms its front wall. The present invention allows a single bag to be easily torn away from the chain of bags.
The method of making the chain of coilable reclosable bags includes supplying a continuous film of plastic web material and moving said film forward in a bag forming direction. A plurality of reclosable fasteners are secured to the surface of the web material, that forms the front wall of each bag, preferably transversely across the web. The web is drawn forward bringing the inside surface of said web material that forms the front wall of each bag next to the surface of a web material that forms the back wall of each bag. The longitudinal edges of the web materials that form the front and back wall of each bag are sealed together to form a tube of plastic web material.
The front wall and back wall of the tube are cross-sealed to each other to form the top and bottom end of each bag. A tearline is cut in the tube between the seals of each bag and the chain of bags are coiled into a roll. The method can include the application of a twin seal with a tearline between them thereby creating a closed top end and a closed bottom end on each bag or a single seal and tearline can be applied which creates an open end and a closed end on each bag. The method of the present invention also include a rupturable line of weakness applied to the front wall of each bag adjacent to the reclosable fastener for entering the bag. The reclosable bags on a roll can be conveniently used by the customer. The reclosable bags of the present invention also have the unique property of being less likely to leak when the bag is placed on its back wall with the reclosable fastener facing up.